One thing I know for sure is people have a hard time sticking to a fitness routine.  Becoming bored with what you are doing leads to people losing momentum and therefore their desire to continue working out regularly.  If you do the same workouts week after week, month after month….3 main things are happening. 1. Those muscles are not being challenged anymore.  They have reached a plateau if you will.  Without changing the load or the movement, the muscle is just doing what it always does and not reaping any more benefits like building more strength or burning the calories you desire.  We want to continue to build strength and stamina throughout our lives. 2. By doing the same workouts, you are missing an opportunity to work other major muscle groups that are  key to our functional fitness.  If all someone is consistently doing is running on a treadmill and some crunches in the corner of the gym they are missing out on soooo much that would not only help with burning more calories & getting this person stronger but would make their everyday activities a piece of cake. 3. You become so bored that you lose interest in...